Closure apparatus

ABSTRACT

A reciprocating rapid acting high-pressure closure apparatus is described for use in injection molding applications and the like. A closure plate is reciprocatingly mounted for movement towards and away from a high-pressure working region to a frame and is moved by a pair of spaced piston and cylinders located alongside a high-pressure force-producing device. A pair of braces are mounted to respective piston and cylinders which are pivotally mounted to the closure plate. The advance of the closure plate by piston-cylinder action is accompanied by a corresponding swivel action of the braces which are swiveled into positive engagement between the closure plate and the force-producing device when the closure plate has neared the end of its advancing stroke at the working region. At the working region the high-pressure force is actuated to produce a high force through the swiveled brace onto the closure plate.

United States Patent Florjancic [54] CLOSURE APPARATUS [72] Inventor: Peter Florjancic, St. Martinstr. 12, Gar- [58] Field of Search ..92/14, 29, 76, 126, 129, 140, 92/148; 74/527, 105

[56] References Cited UNITED STATES PATENTS 2,634,683 4/1953 Anderson ..92/140X 2,799,992 7/1957 Conway ..92/ 140 2,811,143 10/1957 Baines et al.... .....92/148 X 2,897,784 4/1959 Harper ..92/ 140 X 2,95 1,471 9/1960 Hill ..92/140 X 2,989,000 6/ 1961 Alcaro ..92/76 5] Mar. 7, 1972 3,053,112 9/1962 Klingler ..92/ 140 X Primary Examiner-Edgar W. Geoghegan Assistant Examiner-Leslie J. Payne Att0mey-Bryan, Parmelee, Johnson & Bollinger ABSTRACT A reciprocating rapid acting high-pressure closure apparatus is described for use in injection molding applications and the like. A closure plate is reciprocatingly mounted for movement towards and away from a high-pressure working region to a frame and is moved by a pair of spaced piston and cylinders located alongside a high-pressure force-producing device. A pair of braces are mounted to respective piston and cylinders which are pivotally mounted to the closure plate. The advance of the closure plate by piston-cylinder action is accompanied by a corresponding swivel action of the braces which are swiveled into positive engagement between the closure plate and the force-producing device when the closure plate has neared the end of its advancing stroke at the working region. At the working region the high-pressure force is actuated to produce a high force through the swiveled brace onto the closure plate.

8Claims,lDrawingfigure CLOSURE APPARATUS This invention relates to an apparatus for high-pressure closure of working regions such as encountered in injection molding devices and the like. More specifically this invention relates to an apparatus for rapidly advancing and returning a closure member over an extended distance with substantial pressures being applied to the closure member at an extended position.

In an embodiment of an apparatus in accordance with the invention a closure member is adapted to high-pressure seal a working region. The closure member is mounted for reciprocal movement on a frame. The closure member is reciprocated by rapid acting low-pressure pistons which are hydraulically actuated in cylinders. Completion of the advance of the closure member to the working region is accompanied by the automatic positive engagement of a high-forceproducing device to the closure member to provide the desired high-pressure sealing force at the working region with relatively little closure member motion imparted by the highforce-producing device. After the application of the high force the closure member is automatically disengaged from the high-force-producing device and returned to a retracted position by the cylinder-piston.

An advantage of the closure apparatus of this invention over conventional systems for generating rapid extensive movement with low pressure followed by an increase in pressure with a small stroke resides in the stationary frame attachment of the high-force-producing device. The stationary mounting eliminates movable hydraulic fluid conduits.

Sliding closure devices of the conventional type are generally unsatisfactory because of their complicated construction, their tendency to stick and unreliable performance due to wear and tear of the moving parts.

In the described embodiment for a closure apparatus the closure member is connected to the frame with a pair of pistons and cylinders for reciprocal movement thereby along a line of advancement. The pistons and cylinders are respectively pivotally connected to the frame and closure member. A closure force-transferring brace is coupled to the cylinder to pivot therewith. The high-force-producing device is located between and alongside of the piston-cylinder pairs whose pivots are so oriented to pivot the connected closure forcetransferring braces positively between the force-producing device and the closure member when the piston cylinder pairs have advanced the closure member to the working region.

An advantage of the closure apparatus of this invention resides in the swivel action employed in engaging the highforce-producing device with the closure member. The rigid force-transferring brace is swiveled towards and away from the line of advancement in an automatic manner.

In the specific embodiment, the force-transferring brace is provided with a bore to form the cylinder in which the piston is operatively located. When in an operative position the cylinder-shaped brace seats on a selectively oriented surface of the closure member to provide a positive direct engagement between the force-producing device and the closure member.

A single connecting force-transferring brace may be em-' ployed.

Selective positioning of the cylinder-shaped connecting braces provides moment forces on the braces towards the force-producing device while the closure member is advanced to the working region and away from the force-producing device when the closure member is returned. This arrangement of the pivots facilitates position control of the braces.

lt is, therefore, an object of the invention to provide a closure apparatus capable of rapidly reciprocating a closure member towards a working region with high-pressure working in a simple efficient manner with high reliability.

Other advantages and objects of the invention may be understood from the following description of an embodiment in conjunction with the drawing wherein the FIGURE illustrates a partial longitudinal section view of a closure apparatus in accordance with the invention with the upper half of the drawing showing a retracted position and the lower half arranged to show an extended working position of the apparatus.

As shown in the FIGURE, a machine frame 1 is provided with slide shafts ll defining the line of advancement of a closure member 2 slidably mounted on the shafts 1 l. The closure member 2 is in the form of a plate adapted to support, for instance, half of an injection mold (not shown). The closure plate 2 is to be rapidly reciprocated along the shafts 11 with a high molding pressure force to be supplied when the closure plate 2 is in the extended position as illustrated in the lower half of the FIGURE at a working region (not shown).

The upper half of the FIGURE shows the closure plate 2 in a retracted position, prior to plate advancement along the longitudinal working axis of the apparatus.

Reciprocation of the closure plate 2 is obtained with a pair of radially spaced rigid connecting braces 7 in the form of cylinders which operatively enclose pistons 21. The connecting braces 7 are pivotally connected to the closure plate 2 with pins 10 oriented to provide pivot motion in an axial plane, which passes through the longitudinal axis of the machine. Ports l2 and 13 are located in the cylindebshaped braces 7 to pass hydraulic fluid to the cylinder and control positioning of pistons 21.

The pistons 21 are connected to piston rods 8 which in turn are hinged at joints 22 to levers 9. Levers 9 are pivotally connected to frame 1 and seat against stops 23 when the closure plate is in the position illustrated in the top section view. Levers 9 seat against frame 1 when the closure plate 2 is in the position shown in the lower section.

A high-pressure-producing device is located between the connecting braces 7. The pressure device includes a piston 4 operatively located in a cylinder space 5. Ports 6 and 24 allow hydraulic fluid to be applied to the space 5 for position control of piston 4. Piston 4 is provided with seating surfaces such as 18 on a driving plate 3 to receive end surfaces such as 19 on connecting braces 7.

In the operation of the apparatus retracted position of the closure plate 2 is as illustrated in the upper section view of the FIGURE. The hydraulic fluid for piston 4 is applied to port 24 to seat the piston 4 away from closure plate 2 on a stop (not shown) controlled by a screw 16. Hydraulic fluid is also applied to ports 12 in the cylinder braces 7 to return closure plate 2 to its retracted position. The valving for obtaining the hydraulic fluid control is of conventional design and not illustrated.

With the closure plate 2 in the retracted position, piston 21 is so located in the cylinder portion of connecting brace 7 that the piston rod 8 is longitudinally aligned with lever 9. Connecting brace 7 rests on a roller element 17 located on a radially outer edge of drive plate 3.

Hydraulic fluid is now applied to port 13 to thereby advance the closure plate 2 towards the working region. As can be seen in the FIGURE, the pivot pin 10 is located eccentrically relative to the cylinder alignment and away from the high-pressure-producing device. The eccentric location of the pivot introduces a moment force on brace 7 in the direction indicated by arrow A while the closure plate 2 is advanced. The roller element 17 on driving plate 3, however, prevents the brace 7 from pivoting until the seating end surface 19 clears the raidially outer edge of drive plate 3.

Screw 16 has been so adjusted that just prior to mold closure by closure plate 2, the end surface 19 clears the radially outer edge of the drive plate 3 to allow the brace to be pivoted in the direction A by the moment force. Hence, upon completion of the advancing stroke of closure plate 2, the rigid force transferring brace 7 is positively located between the closure plate 2 and drive plate 3. Note that the surface of brace 7 fits flush with a recessed surface in closure plate 2 to provide sturdy interconnection between the piston 4 and closure plate and prevent applying the latter piston force onto closure plate 2 through the pin pivots l0.

Pivot motion of brace 7 was accompanied with a corresponding pivot of lever 9 as illustrated in the lower section view.

Port 6 is then supplied with hydraulic fluid to provide a large force on piston 4. This force is transferred through braces 7 to the closure plate 2 for the desired high marking pressure in the working region.

Return of closure plate 2 is commenced with a discharge of hydraulic fluid from cylinder space 5 and an application of hydraulic fluid to port 12 in the cylinders of the braces. Piston 4 is pressed back onto adjusting screw 16 and brace 7 is pivoted away from driving plate 3 by a moment force having a direction indicated by arrow B. The latter pivot motion returns the lever 9 and piston rod 8 in straight alignment with lever 9 against stop 23. The continued application of hydraulic fluid to port 12 allows the piston-cylinder action to return closure plate 2 to its retracted position.

A hydraulic. actuated ejector 15 is provided to eject completed molded articles. Ejector 15 operates through a suitable opening in closure plate 2.

The retraction of the closure plate 2 now enables a repeat of the described operation. The use of the known elbow linkages in closure apparatus generally are only usable for limited strokes. The closure device of this invention enables a great degree of freedom in selecting operating speeds, adjustments and adaptability to different stroke lengths.

Modifications of the described structural details may be implemented within the scope of the invention. For instance, the swivel feature of the brace can be obtained with appropriately shaped surfaces on the cylinder instead of pivot pins 10. Piston rod 8 may be braced to act over roller elements to reduce hydraulic fluid consumption. Piston 4 may be replaced with a moving cylinder. Brace 7 may be a separate member with a separate cylinder connected thereto.

What is claimed is:

1. An apparatus for rapidly reciprocating a closure member to a working region for high-pressure closure of the working region such as in injection molding devices and the like, comprising a frame and a closure member, said closure member being mounted to the frame for reciprocal movement along a line of advancement to effect a closure of the working region,

means for producing a high-pressure force,

a rapid acting means for rapidly reciprocatingly moving the closure member along the line of advancement towards and away from the working region, and

normally decoupled rigid high-force-transferring means actuated in the vicinity of the completion of the advance of the closure member for positively engaging the closure member and operatively rigidly coupling the high-forceproducing means to the closure member for high-pressure closure of the working region.

2. The rapid closure member reciprocating apparatus as claimed in claim 1 wherein said high-force-transferring means further includes a rigid brace pivotally mounted to the closure member and coupled to the rapid acting means for pivot position control thereby with said pivot mounting located to swivel the rigid brace positively between the closure member and the high-force-producing means, near completion of closure member advance and with said rigid member being pivoted away from the closure member surface and the high-force-producing means during return of the closure member.

3. The rapid closure member reciprocating apparatus as claimed in claim 2 wherein said rapid acting means comprises an operatively engaged fluid-actuated piston and cylinder located alongside the force-producing means, said cylinder and rigid brace being associated with one another for joint pivot motion towards and away from the force-producing means, said piston being provided with a piston rod extending through the cylinder in pivot engagement with the frame, said pivot mounting at the closure member being eccentrically located away from the force-producing means to provide a moment force on the rigid brace towards the force producing means during advancement of the closure member and away from the force-producing means during retraction of the closure member.

4. The rapid closure member reciprocating apparatus as claimed in claim 3 wherein the force producing means further comprises a working cylinder and working piston provided with an action plate facing said closure member, said action plate having a seating surface shaped to receive the pivoted rigid brace near completion of the advancement of the closure member, said working piston being operatively located in the working chamber for fluid pressurization of the working piston towards the closure member.

5. An apparatus for rapidly reciprocating a closure member to a working region for high-pressure closure of the working region such as in injection molding devices and the like comprising a frame and a closure member mounted for reciprocal movement to the frame along a line of advancement to effect a closure of the working region on a front side of the member,

a pair of spaced reciprocating devices in the form of cylinders extending rearwardly along the line of advancement from the closure member, each of said cylinders enclosing fluid-actuated pistons, with said pistons provided with piston rods,

means for producing a large force, said force-producing means being located between the pair of cylinders and pistons and oriented to operatively face the closure members,

said advancing devices being pivotally mounted to the closure member with pivot orientations selected to pivot the advancing devices towards and away from the forceproducing means, said pivots further being located away from the force-producing means to form a moment force tending to pivot the reciprocating devices towards the force-producing means during closure member advancement to the working region, and form a moment force tending to pivot the reciprocating devices away from the force-producing means during return of the closure member from the working region,

said force-producing means being provided with a seating surface oriented and sized to positively locate rigid portions of the reciprocating devices between the seating surface and the closure member when positioned at the working region.

6. The apparatus for rapidly reciprocating a closure member and high-pressure working thereof as claimed in claim 5 wherein said piston rods each include a lever pivotally interconnecting the piston rods to the frame, with cylinders pivoted to the closure member, said levers each having a first stable pivot position in alignment with the piston rod for rapid advance of the closure member, said levers each having a second stable pivot position when folded relative to the piston rod to accommodate pivot motion of the cylinders towards the force producing means.

7. The apparatus for rapidly reciprocating a closure member with high-pressure actuation thereof at a working region as claimed in claim 6 wherein said force-producing means includes a drive plate oriented to face the closure member and located between the cylinders to space the cylinders during closure member advance towards the working re gion, said drive plate being provided with a seating surface to receive the rigid portions of the reciprocating device.

8. The apparatus for rapidly reciprocating a closure member and high-pressure working thereof as claimed in claim 7, wherein said closure member is provided with cylinder seating surfaces oriented to provide transverse flush seating surfaces for the cylinder portions after pivoting thereof near completion of closure member advance.

1i i i 

1. An apparatus for rapidly reciprocating a closure member to a working region for high-pressure closure of the working region such as in injection molding devices and the like, comprising a frame and a closure member, said cloSure member being mounted to the frame for reciprocal movement along a line of advancement to effect a closure of the working region, means for producing a high-pressure force, a rapid acting means for rapidly reciprocatingly moving the closure member along the line of advancement towards and away from the working region, and normally decoupled rigid high-force-transferring means actuated in the vicinity of the completion of the advance of the closure member for positively engaging the closure member and operatively rigidly coupling the high-force-producing means to the closure member for high-pressure closure of the working region.
 2. The rapid closure member reciprocating apparatus as claimed in claim 1 wherein said high-force-transferring means further includes a rigid brace pivotally mounted to the closure member and coupled to the rapid acting means for pivot position control thereby with said pivot mounting located to swivel the rigid brace positively between the closure member and the high-force-producing means, near completion of closure member advance and with said rigid member being pivoted away from the closure member surface and the high-force-producing means during return of the closure member.
 3. The rapid closure member reciprocating apparatus as claimed in claim 2 wherein said rapid acting means comprises an operatively engaged fluid-actuated piston and cylinder located alongside the force-producing means, said cylinder and rigid brace being associated with one another for joint pivot motion towards and away from the force-producing means, said piston being provided with a piston rod extending through the cylinder in pivot engagement with the frame, said pivot mounting at the closure member being eccentrically located away from the force-producing means to provide a moment force on the rigid brace towards the force producing means during advancement of the closure member and away from the force-producing means during retraction of the closure member.
 4. The rapid closure member reciprocating apparatus as claimed in claim 3 wherein the force producing means further comprises a working cylinder and working piston provided with an action plate facing said closure member, said action plate having a seating surface shaped to receive the pivoted rigid brace near completion of the advancement of the closure member, said working piston being operatively located in the working chamber for fluid pressurization of the working piston towards the closure member.
 5. An apparatus for rapidly reciprocating a closure member to a working region for high-pressure closure of the working region such as in injection molding devices and the like comprising a frame and a closure member mounted for reciprocal movement to the frame along a line of advancement to effect a closure of the working region on a front side of the member, a pair of spaced reciprocating devices in the form of cylinders extending rearwardly along the line of advancement from the closure member, each of said cylinders enclosing fluid-actuated pistons, with said pistons provided with piston rods, means for producing a large force, said force-producing means being located between the pair of cylinders and pistons and oriented to operatively face the closure members, said advancing devices being pivotally mounted to the closure member with pivot orientations selected to pivot the advancing devices towards and away from the force-producing means, said pivots further being located away from the force-producing means to form a moment force tending to pivot the reciprocating devices towards the force-producing means during closure member advancement to the working region, and form a moment force tending to pivot the reciprocating devices away from the force-producing means during return of the closure member from the working region, said force-producing means being provided with a seating surface oriented and sized to positively locate rigid portionS of the reciprocating devices between the seating surface and the closure member when positioned at the working region.
 6. The apparatus for rapidly reciprocating a closure member and high-pressure working thereof as claimed in claim 5 wherein said piston rods each include a lever pivotally interconnecting the piston rods to the frame, with cylinders pivoted to the closure member, said levers each having a first stable pivot position in alignment with the piston rod for rapid advance of the closure member, said levers each having a second stable pivot position when folded relative to the piston rod to accommodate pivot motion of the cylinders towards the force producing means.
 7. The apparatus for rapidly reciprocating a closure member with high-pressure actuation thereof at a working region as claimed in claim 6 wherein said force-producing means includes a drive plate oriented to face the closure member and located between the cylinders to space the cylinders during closure member advance towards the working region, said drive plate being provided with a seating surface to receive the rigid portions of the reciprocating device.
 8. The apparatus for rapidly reciprocating a closure member and high-pressure working thereof as claimed in claim 7, wherein said closure member is provided with cylinder seating surfaces oriented to provide transverse flush seating surfaces for the cylinder portions after pivoting thereof near completion of closure member advance. 